This invention relates to automatic fire extinguishing sprinklers, and, more particularly, to a new and improved adjustable concealed sprinkler having a cover and a deflector which are releasable in response to elevated temperature conditions.
Heretofore, certain concealed sprinklers having a releasable cover concealing the sprinkler, such as the sprinklers described in U.S. Pat. Nos. 4,014,388 and 4,066,129, have had a movable deflector which normally presses against the cover. With such arrangements, however, the continuous pressure applied to the cover may tend to cause cold flow of a solder bond which is intended to hold the cover in position until an elevated temperature releases it. In other forms of concealed sprinklers, such as those shown in U.S. Pat. Nos. 2,389,331, 3,459,266, 3,633,676 and 3,714,989, the deflector, as well as a cap or plug sealing the liquid outlet, are held in place by a thermally responsive lever arrangement extending across the sprinkler frame which requires additional space between the deflector and the cover.
Accordingly, it is an object of the present invention to provide a new and improved adjustable concealed sprinkler which overcomes the above-mentioned disadvantages of the prior art.
Another object of the present invention is to provide an adjustable concealed sprinkler having a movable deflector which is effectively retained away from the cover plate until the sprinkler has been actuated by an elevated temperature condition.
A further object of the invention is to provide a new and improved adjustable concealed sprinkler of the center strut type wherein sprinkler actuation is effected more rapidly after an elevated temperature condition has been attained.
An additional object of the invention is to provide an improved adjustable concealed sprinkler having a movable deflector in which the deflector is more securely held when in the extended position.